        :root {
            --primary: #2563eb;
            --primary-dark: #1d4ed8;
            --secondary: #7c3aed;
            --accent: #4f46e5;
            --light: #f8fafc;
            --dark: #0f172a;
            --text: #334155;
            --text-light: #64748b;
            --border: #e2e8f0;
            --success: #10b981;
            --warning: #f59e0b;
            --danger: #ef4444;
            --info: #3b82f6;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
        }

        body {
            background-color: #f1f5f9;
            color: var(--text);
            line-height: 1.5;
        }

        a {
            text-decoration: none;
            color: inherit;
        }

        .container {
            max-width: 1600px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* 顶部导航 */
        .top-nav {
            background-color: white;
            box-shadow: 0 1px 3px rgba(0,0,0,0.1);
            position: sticky;
            top: 0;
            z-index: 100;
        }

        .nav-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            height: 70px;
        }

        .logo {
            display: flex;
            align-items: center;
            font-size: 24px;
            font-weight: 700;
            color: var(--primary);
        }

        .logo-icon {
            margin-right: 10px;
            color: var(--accent);
        }

        .nav-links {
            display: flex;
            gap: 25px;
        }

        .nav-link {
            font-weight: 500;
            color: var(--text);
            padding: 8px 12px;
            border-radius: 6px;
            transition: all 0.2s;
        }

        .nav-link:hover, .nav-link.active {
            color: var(--primary);
            background-color: rgba(37, 99, 235, 0.1);
        }

        .nav-link.active {
            font-weight: 600;
        }

        .user-actions {
            display: flex;
            align-items: center;
            gap: 20px;
        }

        .search-bar {
            position: relative;
        }

        .search-bar input {
            padding: 10px 15px 10px 40px;
            border: 1px solid var(--border);
            border-radius: 6px;
            width: 280px;
            font-size: 14px;
            transition: all 0.2s;
        }

        .search-bar input:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
        }

        .search-icon {
            position: absolute;
            left: 12px;
            top: 50%;
            transform: translateY(-50%);
            color: var(--text-light);
        }

        .points-badge {
            background-color: var(--primary);
            color: white;
            padding: 6px 12px;
            border-radius: 20px;
            font-size: 14px;
            font-weight: 500;
            display: flex;
            align-items: center;
            gap: 6px;
        }
        /* 主布局 */
        .main-layout {
            display: grid;
            grid-template-columns: 280px 1fr;
            gap: 30px;
            margin-top: 30px;
        }

        /* 侧边栏 */
        .sidebar {
            position: sticky;
            top: 90px;
            height: calc(100vh - 120px);
            overflow-y: auto;
            padding-right: 10px;
        }

        .sidebar-section {
            background-color: white;
            border-radius: 12px;
            box-shadow: 0 1px 3px rgba(0,0,0,0.05);
            padding: 20px;
            margin-bottom: 20px;
        }

        .sidebar-title {
            font-size: 16px;
            font-weight: 600;
            margin-bottom: 16px;
            color: var(--dark);
            display: flex;
            align-items: center;
            gap: 8px;
        }

        /* 签到卡片 */
        .checkin-card {
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            color: white;
            padding: 20px;
            border-radius: 12px;
            margin-bottom: 20px;
        }

        .checkin-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 15px;
        }

        .checkin-title {
            font-size: 18px;
            font-weight: 600;
        }

        .checkin-days {
            background-color: rgba(255,255,255,0.2);
            padding: 4px 10px;
            border-radius: 20px;
            font-size: 14px;
        }

        .checkin-desc {
            font-size: 14px;
            opacity: 0.9;
            margin-bottom: 20px;
        }

        .checkin-btn {
            background-color: white;
            color: var(--primary);
            border: none;
            padding: 10px;
            border-radius: 6px;
            font-weight: 600;
            cursor: pointer;
            width: 100%;
            transition: all 0.2s;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
        }

        .checkin-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        }

        .checkin-btn:active {
            transform: translateY(0);
        }

        .checkin-btn.disabled {
            background-color: var(--border);
            color: var(--text-light);
            cursor: not-allowed;
        }

        /* 进度条 */
        .progress-item {
            margin-bottom: 15px;
        }

        .progress-info {
            display: flex;
            justify-content: space-between;
            margin-bottom: 6px;
            font-size: 14px;
        }

        .progress-name {
            color: var(--text);
        }

        .progress-percent {
            color: var(--primary);
            font-weight: 500;
        }

        .progress-bar {
            height: 6px;
            background-color: var(--border);
            border-radius: 3px;
            overflow: hidden;
        }

        .progress-fill {
            height: 100%;
            background: linear-gradient(90deg, var(--primary), var(--accent));
            border-radius: 3px;
        }

        /* 资源列表 */
        .resource-list {
            list-style: none;
        }

        .resource-item {
            padding: 12px 0;
            border-bottom: 1px solid var(--border);
        }

        .resource-item:last-child {
            border-bottom: none;
        }

        .resource-link {
            display: flex;
            align-items: center;
            gap: 12px;
            transition: color 0.2s;
        }

        .resource-link:hover {
            color: var(--primary);
        }

        .resource-icon {
            width: 32px;
            height: 32px;
            background-color: rgba(37, 99, 235, 0.1);
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--primary);
        }

        .resource-name {
            font-size: 14px;
            font-weight: 500;
        }
   .ai-text{
		   font-weight: 500;
		   color:  #4d4dff;
		   padding: 8px 12px;
		   border-radius: 6px;
		   transition: all 0.2s;
		}
		.ai-text:hover,.ai-text.active {
			color: var(--primary);
			background-color: rgba(37, 99,235,0.1);
		}
		.ai-text.active{
			font-weight: 600;
		}
        /* 主内容区 */
        .content-area {
            display: flex;
            flex-direction: column;
            gap: 30px;
        }

        .section {
            background-color: white;
            border-radius: 12px;
            box-shadow: 0 1px 3px rgba(0,0,0,0.05);
            padding: 25px;
        }

        .section-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 20px;
        }

        .section-title {
            font-size: 20px;
            font-weight: 600;
            color: var(--dark);
        }

        .section-link {
            color: var(--primary);
            font-size: 14px;
            font-weight: 500;
            display: flex;
            align-items: center;
            gap: 6px;
            transition: all 0.2s;
        }

        .section-link:hover {
            text-decoration: underline;
        }

        /* 课程网格 */
        .course-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 20px;
        }

        .course-card {
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 1px 3px rgba(0,0,0,0.05);
            transition: all 0.3s;
            background-color: white;
            border: 1px solid var(--border);
        }

        .course-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 15px rgba(0,0,0,0.1);
            border-color: rgba(37, 99, 235, 0.2);
        }

        .course-image {
            height: 160px;
            background-color: #f8fafc;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--text-light);
            position: relative;
            overflow: hidden;
        }

        .course-tag {
            position: absolute;
            top: 12px;
            right: 12px;
            background-color: var(--warning);
            color: white;
            padding: 4px 10px;
            border-radius: 4px;
            font-size: 12px;
            font-weight: 500;
            z-index: 1;
        }

        .course-info {
            padding: 18px;
        }

        .course-title {
            font-size: 16px;
            font-weight: 600;
            margin-bottom: 8px;
            color: var(--dark);
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        .course-meta {
            display: flex;
            justify-content: space-between;
            font-size: 13px;
            color: var(--text-light);
            margin-bottom: 12px;
        }

        .course-instructor {
            display: flex;
            align-items: center;
            gap: 6px;
        }

        .course-stats {
            display: flex;
            align-items: center;
            gap: 6px;
        }

        .course-rating {
            color: var(--warning);
            font-size: 14px;
        }

        .course-price {
            font-size: 16px;
            font-weight: 600;
            color: #f59e0b;
        }

        .free-badge {
            background-color: var(--success);
            color: white;
            padding: 4px 8px;
            border-radius: 4px;
            font-size: 12px;
            font-weight: 500;
        }

        /* 资源列表样式 */
        .resource-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            gap: 20px;
        }

        .resource-card {
            display: flex;
            align-items: center;
            padding: 16px;
            border-radius: 8px;
            background-color: white;
            box-shadow: 0 1px 3px rgba(0,0,0,0.05);
            border: 1px solid var(--border);
            transition: all 0.3s;
        }

        .resource-card:hover {
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            border-color: rgba(37, 99, 235, 0.2);
        }

        .resource-icon-lg {
            width: 48px;
            height: 48px;
            background-color: rgba(37, 99, 235, 0.1);
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-right: 16px;
            color: var(--primary);
            font-size: 20px;
            flex-shrink: 0;
        }

        .resource-content {
            flex: 1;
            min-width: 0;
        }

        .resource-title {
            font-weight: 600;
            margin-bottom: 6px;
            color: var(--dark);
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }

        .resource-desc {
            font-size: 13px;
            color: var(--text-light);
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        /* 底部 */
        footer {
            background-color: var(--dark);
            color: white;
            padding: 50px 0 30px;
            margin-top: 60px;
        }

        .footer-container {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 40px;
        }

        .footer-column h3 {
            font-size: 16px;
            font-weight: 600;
            margin-bottom: 20px;
            color: white;
        }

        .footer-links {
            list-style: none;
        }

        .footer-links li {
            margin-bottom: 12px;
        }

        .footer-links a {
            color: rgba(255,255,255,0.7);
            font-size: 14px;
            transition: color 0.2s;
        }

        .footer-links a:hover {
            color: white;
        }

        .footer-bottom {
            border-top: 1px solid rgba(255,255,255,0.1);
            margin-top: 40px;
            padding-top: 20px;
            text-align: center;
            color: rgba(255,255,255,0.5);
            font-size: 14px;
        }

        /* 响应式调整 */
        @media (max-width: 1200px) {
            .main-layout {
                grid-template-columns: 240px 1fr;
                gap: 20px;
            }
            
            .course-grid {
                grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            }
        }

        @media (max-width: 992px) {
            .main-layout {
                grid-template-columns: 1fr;
            }
            
            .sidebar {
                position: static;
                height: auto;
            }
            
            .nav-links {
                display: none;
            }
        }

        @media (max-width: 768px) {
            .search-bar input {
                width: 200px;
            }
            
            .footer-container {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 576px) {
            .nav-container {
                flex-direction: column;
                height: auto;
                padding: 15px 0;
            }
            
            .logo {
                margin-bottom: 15px;
            }
            
            .user-actions {
                width: 100%;
                justify-content: space-between;
            }
            
            .search-bar input {
                width: 100%;
            }
            
            .course-grid, .resource-grid {
                grid-template-columns: 1fr;
            }
            
            .footer-container {
                grid-template-columns: 1fr;
            }
        }
        